I/O Settings
The RS-422/485 ComProbe allows the user plenty of options for monitoring various serial communication setups. The I/O Settings dialog allows the user to configure the setup.
The RS-422/485 ComProbe supports data rates up to 921.6Kbps. The user can pick one of the standard rates in the drop down box in the I/O Settings dialog. For non-standard rates, the user can simply type in the value in the box.
The RS-422/485 ComProbe can monitor serial communications with 5, 6, 7 or 8 data bits and with 1, 1.5 or 2 stop bits. The device also supports all the standard parity types (None, Odd, Even, Mark, Space, and Ignore).
The user can also choose the bit order on their serial communication circuit. The choices are either LSB (least significant bit) first or MSB (most significant bit) first. LSB first is normal, while MSB first is considered "reversed" from normal. This option reverses the order of the bits within each byte.
The user can also choose to monitor either DTE only, DCE only or both DTE and DCE ends of the communication.
Pin Out and Cabling Information
The RS-422/485 ComProbe can be used for monitoring both 2-wire and 4-wire RS-422/485 communication circuits. The pin-out information for the RS-422/485 ComProbe is shown in the table below:
| PIN | Signal Definition |
| 1 | TX+ |
| 2 | TX- |
| 3 | RTS+ |
| 4 | RTS- |
| 5 | GND |
| 6 | RX+ |
| 7 | RX- |
| 8 | CTS+ |
| 9 | CTS- |
For 2-wire circuits, Serialtest expects to see the transmit lines of your circuit connected to the corresponding pins on the RS-422/485 ComProbe. Tap off of the Transmit + line (TX+) of your circuit, and connect that to pin 6 (RX+) on the RS-422/485 ComProbe, then tap off of the Transmit - line (TX-) and connect that to pin 7 (RX-) on the RS-422/485 ComProbe.
For a four wire circuit, the procedure is the same. Tap off of the Transmit + line (TX+) of your circuit, and connect that to pin 6 (RX+) on one ComProbe, then tap off of the Transmit †line (TXâ€Â) and connect that to pin 7 (RXâ€Â) on the ComProbe. Do the same with the Receive lines, tap off of the RX+ and connect that to pin 1 on the ComProbe then tap RX†and send it to pin 2 on the ComProbe.
More details about wiring information for these configurations are available in this document.
Frontline's new licensing scheme allows you to share the analyzer among different platforms used by different individuals. A desktop user would simply park his key, download it to his laptop and head to the remote site exhibiting symptoms of a problem.
To learn more about testing, troubleshooting and debugging Serial communications networks, download a Serialtest demo. You can also order your copy of Serialtest online.
